C++ Iterator Library - input_iterator_tag

Description

It is used to identify the category of an iterator as an input iterator and all input iterators support at least one the following operations.

property	valid expressions
It is a copy-constructible, copy-assignable and destructible	`X b(a);` `b = a;`
It can be compared for equivalence using the equality/inequality operators (meaningful if both iterators are be in domain).	`a == b` `a != b`
It can be dereferenced as an rvalue (if in a dereferenceable state).	`*a` `a->m`
It can be incremented (if in a dereferenceable state). The result is either also dereferenceable or a past-the-end iterator. The previous iterator value is not required to be dereferenceable after the increase.	`++a` `(void)a++` `*a++`
Its value type does not need to be assignable	`t = u` not required

property	valid expressions
It is a copy-constructible, copy-assignable and destructible	`X b(a);` `b = a;`
It can be compared for equivalence using the equality/inequality operators (meaningful if both iterators are be in domain).	`a == b` `a != b`
It can be dereferenced as an rvalue (if in a dereferenceable state).	`*a` `a->m`
It can be incremented (if in a dereferenceable state). The result is either also dereferenceable or a past-the-end iterator. The previous iterator value is not required to be dereferenceable after the increase.	`++a` `(void)a++` `*a++`
Its value type does not need to be assignable	`t = u` not required
Lvalues are swappable.	`swap(a,b)`

Following is the declaration for std::input_iterator_tag.

struct input_iterator_tag {};

iterator.htm

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